Bushing terminal and line lead guard



Feb. 24, 1959 c. E. SUTTON, JR susamc; TERMINAL AND-1m: LEAD GUARD Filo d Oct. 3.,1956

lip 0775f 7 7 fi M United States Patent 2,875,267 BUSHING TERMINALANDLINELEADGUARD Clement E. Sutton,Jr., Schenectady,,N. Y., asslgnor to General Electric Company, a corporation of New York Application 0ctober.3,.1956,-Serial.-No. 613,768

1 Claim. (Cl.174-'139) This invention relates to a guard, and more particularly, to a guard for the bushing terminal and connected line lead of an electrical apparatus.

In the transformer art outages have been experienced, and I have discovered that some of these outages have been caused by animals whose bodies have presented a short circuit path between the grounded transformer tank and the tank mounted terminal bushing and line lead connected thereto. For instance, in the distribution transformer art it is conventional practice to have a generally upright bushing mounted on the cover of the transformer tank and to connect a generally vertically disposed line lead to the terminal on the upper end of the bushing. In the past many ditlerent forms of insulating caps have been used to prevent animals positioned on the tank cover from coming in contact with the bushing terminal and grounding the apparatus as well as electrocuting themselves. However, in some instances animals have been able to dislodge the caps, and in other cases animals have caused outages by spanning the bared line lead at its area of entry into the top of the cap and the grounded tank cover.

Therefore, it is an object of this invention to provide an improved guard for the bushing terminal and line lead of an electrical apparatus.

In my invention I provide a guard which besides having a main cap portion which surrounds the bushing terminal also has a narrow neck or tubular portion which surrounds the line lead for a substantial length thereof beyond the bushing terminal. In this manner animals cannot reach the conductor while in contact with the apparatus. This narrow neck or tubular portion is an integral part of the cap whereby no separate insulating material tube or taping is required for the line lead. Additionally, the end of the narrow neck or tubular portion which is most remote from the apparatus is provided with a clamp which is out of the reach of animals that are in contact with the apparatus. This clamp clamps the guard and line lead with respect to each other so that after the cap is snugly seated on the bushing the guard cannot be readily dislodged by animals in attempting to have ingress to the bushing terminal.

While the specification concludes wtih the claim particularly pointing out and distinctly claiming the subject matter which I regard as my invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawing in which:

Fig. l is a side elevation view of one form of my invention; and

Fig. 2 is an enlarged and sectional side elevation view of the guard of Fig. l; and

Fig. 3 is an enlarged perspective view of the guard of Fig. 1.

Shown in the drawing is a conventional distribution transformer tank 1 having a generally upright bushing 2,875,26? Patented Feb. 24, 1959 Zmounted on the tank cover 3. The upper'end of the bushing 2 has a terminal thereon which is indicated generally by the reference numeral 4 in Fig. 2. .A gen erally vertically disposed line lead 5 is connected to the terminal 4 and extends up through a guard 6 which is snugly seated on the upper end of the bushing. Mounted on a side wall of the tank is a lightning arrester 7. The upper end of lightning arrester 7 has an electrode 8 extending therefrom towards an electrode 9 of the terminal 4. Electrodes 8 and 9 are spaced from each other by an air gap 10.

Theguard 6 has a hollow cap portion 11 and a hollow and narrow neck or tubular portion 12 which are integral with each other. The upper end of the neck '12 has a line lead clamp indicated generally by reference numeral 13. Clamp 13 comprises a metallic collar 14, a screw 15, a lock nut 16, and a clamping block or pad 17 which is carried by the inner end of screw 15. The parts are assembled by first loosening the clamp 13 so that the lower end of line lead 5 can be inserted into the upper end of guard 6 and then guard 6 is pushed up along lead 5 so that the lower end of lead 5 can be connected to terminal 4. Then guard 6 is lowered along the lead 5 and snugly seated on the upper end of bushing 2. Thereafter the lead 5 is pulled up tautly and the clamp 13 is firmly clamped and locked with respect to the lead 5 so that the guard cannot be unseated from the upper end of the bushing 2.

The guard 6 is made from electrical insulating material which has good weathering characteristics, and prefer ably from a rubber base electrical insulating material or the like so that it will not be frangible but somewhat flexible. Additionally, the neck 12 which is superposed with respect to the cap 11 extends along the lead 5 in surrounding relationship for a substantial distance so that the largest of animals which are known to climb line poles cannot reach the lead 5 while standing on tank cover 3.

The open base of the cap 11 has a plurality of drain notches 18 formed in its rim so that water which enters the top of guard 6 will run out from the bottom thereof. Additionally, a side wall opening 19 is provided in the cap 11 for the electrode 9, and the air gap 10 between the electrodes 8 and 9 is wind shielded by two exterior side Walls 20 and an exterior bottom wall 21 which extend aiong the opening 19. Of course, if no gapped lightning arrester such as unit 7 is used in conjunction with the cover mounted bushing 2. then no opening 19 will be provided and walls 26 and 21 will be omitted.

It will now be apparent that my invention provides a unitary or single piece guard for a bushing terminal and line lead connected thereto which cannot be easily dislodged. Additionally, my guard is low in cost and easy to fabricate, and can be conveniently assembled in final position.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and there fore, it is intended by the appended claim to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

In an electrical apparatus which is housed in a tank which has a cover, a generally upright bushing mounted on said cover, the upper end of said bushing having an electrical terminal thereon for receiving an electrical line lead, and a generally vertically disposed bare line 1 lead being connected to said terminal, means for protecttrical insulating material member having a hollow cap and a vertically superposed narrow and hollow neck which are integrally connected to each other, said cap being snugly seated on the upper end of said bushing and surrounding said terminal, and said neck extending from saidcap forla substantial distance about said line lead, the upper endtof said neck having a manually operable clamp for clamping said guard and line lead with respect to each other, and said clamp comprising a collar which is connected to the upper end of said neck, a. side of said collar having a threaded aperture and a thumb screw extending through said aperture for clamping said line lead to said collar, and a generally upright electrical insulating material encased lightning arrestcr mounted on the side of said tank adjacent to said bushing, the lower end of said lightning arrester having a connection to ground and the upper end of said lightning arrester having a gapped connection to said terminal, said gapped connection comprising a wind shielded aperture in said ca and a pair of electrodes which are connected to said terminal and lightning arrester upper end at one of their ends and at their other ends are positioned adjacent to each other in spaced relationship in said shielded'aperture.

References Cited in the tile of this patent UNITED STATES PATENTS Rogofi Apr. 14, 1953 Mam 4 

